Question: What do the following two equations represent? $2x+2y = -2$ $-6x+6y = -2$
Answer: Putting the first equation in $y = mx + b$ form gives: $2x+2y = -2$ $2y = -2x-2$ $y = -1x - 1$ Putting the second equation in $y = mx + b$ form gives: $-6x+6y = -2$ $6y = 6x-2$ $y = 1x - \dfrac{1}{3}$ The slopes are negative inverses of each other, so the lines are perpendicular.